Exercise Part 2: As Clear as Mud

In this blog let’s try to part the muddied waters around exercise recommendations. For starters the government acknowledged the confusion around these exercise recommendations. Trying to separate out physical activity recommendations according to chronic disease. Since exercise science is a fairly new area research they don’t have a lot of long-term data out there.

At this time they thought that it would be best to have it be a part of the dietary guidelines. The science originated in 1980 with the revision every 5 years. For the first time physical activity was included in 2005.
In 2005 the dietary guidelines proposed to separate recommendations on physical activity. The  first primary recommendation was to reduce risk of chronic disease . This recommendation was that adulthood people should engage in at least 30 minutes of moderate-intensity physical activity.

Weight management vs Weight prevention

The second recommendation focused more on weight management. In an attempt to manage body weight and prevent gradual unhealthy weight gain in adulthood.The recommendation set by the government for the purpose of weight control was that individuals should engage in approximately 60 Minutes of moderate-to-vigorous intensity physical activity.
One of the biggest challenges that we’re now faced with recommendations around physical activity is that most study designs looked at observational data. When they looked at data they did not look at response to dose meaning. Obviously an 85 year old man is going to have a different outcome than a 17 year old male. They also struggled to have equal comparisons of activities that were measured .Some studies looked at leisure time physical activities versus some looked at physical activity obtained from activities of daily living.

Out with old, in with the New.. kind of

What most people have missed is that they have updated in 2008 but it hasn’t seem to spread with these new messages. For a full report of recommendations now ranging from preschool to Seniors click here: https://www.hhs.gov/fitness/be-active/physical-activity-guidelines-for-americans/index.html

Here are some summarized messages for Adults:

  • Move more, sit less. If you have to sit then you should aim for more of the moderate-to-vigorous physical activity.
  • Directly from the article for substantial health benefits:
    • adults should do at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) a week of moderate-intensity,
    • or 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity,
    • or an equivalent combination of moderate- and vigorous-intensity aerobic activity. Preferably, aerobic activity should be spread throughout the week.
  • Additional health benefits are gained by engaging in physical activity beyond the equivalent of 300 minutes (5 hours) of moderate-intensity physical activity a week.
  • Aim to do muscle-strengthening activities such as strength training. Try to involve all major muscle groups at least 2 or more days. You will need 48 hours recovery in between working muscle groups.

How do you know your exercise intensity?

Because intensities vary according to the person’s fitness level here is a simple guide from the Mayo Clinic

Moderate activity feels somewhat hard. Here are clues that your exercise intensity is at a moderate level:

  • Your breathing quickens, but you’re not out of breath.
  • You develop a light sweat after about 10 minutes of activity.
  • You can carry on a conversation, but you can’t sing.

Low intensity would the opposite of these statements.

Vigorous activity feels challenging. Here are clues that your exercise intensity is at a vigorous level:

  • Your breathing is deep and rapid.
  • You develop a sweat after only a few minutes of activity.
  • You can’t say more than a few words without pausing for breath.

In conclusion these recommendations do provide a clearer idea of what is recommended minimum of movement. However, I feel a grave injustice is done by not defining a maximum. Just as we would with nutrients we need a threshold to protect those that may abuse exercise. Stay tuned for my next blog to discuss just that!